1. Field of the Invention
The present invention relates to a method for performing processing of a workpiece using laser beams, and an apparatus which implements this method.
2. Description of the Related Arts
Heretofore, when using laser beam irradiation to cut or weld a workpiece, or to remove only a specified layer from the surface of a workpiece, for example, there have been cases in which laser beams of differing intensities and wavelengths are irradiated in multiple stages, such as preliminary heat treatment and main processing, or removal of a first layer and removal of a second layer.
Japanese Patent Application Kokai Publication No. H08-10970 discloses a technology for raising the processing efficiency in such cases, which uses an array of as many laser oscillators as the number of layers to be processed, each emitting a laser beam effective to a specific layer, for example.
Moreover, Japanese Patent Application Kokai Publication No. 2002-270994 discloses a technology in which a plurality of laser oscillators for emitting laser beams of differing wavelengths are disposed so that the laser beams are emitted along the same axis, and ON/OFF control of the various laser beams is used to irradiate laser beams of differing wavelengths onto a workpiece.
In patterning of an electronic circuit board, laser processing is carried out by moving either a board or a laser beam irradiation in an X-Y direction, for example.
In the case of such patterning of an electronic circuit board, the following problems arise in the technologies of Japanese Patent Application Kokai Publication No. H08-10970 and Patent Reference 2, when laser beams of differing intensities and wavelengths are irradiated in multiple stages.
First, in the case of the technology of Japanese Patent Application Kokai Publication No. H08-10970, laser oscillators are arrayed as many as the number of layers to be processed, and thus the board or the laser beam irradiation must be moved over an extra distance in the X-direction and in the Y-direction, resulting in the problems of reduced processing efficiency and reduced productivity.
Furthermore, in the case of the technology of Japanese Patent Application Kokai Publication No. H08-10970, since there is a previously determined relative irradiation position of the laser beams emitted from the laser oscillators which are arrayed as many as the number of the layers to be processed, there is the problem that processing is impossible in cases where the board or the laser beam irradiation moves in the reverse direction.
In the case of the technology of Japanese Patent Application Kokai Publication No. 2002-270994, since laser beams of differing wavelengths are irradiated along the same axis, it is impossible to continuously process a plurality of layers. Consequently, this leads to the problems of reduced processing efficiency and reduced productivity, as when the technology of Japanese Patent Application Kokai Publication No. H08-10970 is employed.
The problems to be solved by the present invention are the reduced processing efficiency and the reduced productivity that result when the prior art is employed in patterning of an electronic circuit board, using laser beams of differing intensities and wavelengths irradiated in multiple stages.